A Case of Inverted Papilloma of The Mastoid Cavity After Cholesteatoma Surgery.

An inverted papilloma is a benign neoplasm that occurs exclusively in the sinonasal cavity; an inverted papilloma involving the mastoid cavity is extremely rare. We present the case of a patient with an inverted papilloma of the mastoid cavity secondary to cholesteatoma surgery. No case that occurred after acquired cholesteatoma has been reported in literature. A 39-year-old female who was diagnosed with cholesteatoma was treated with a modified radical mastoidectomy in 1988. After recurrence, the patient underwent a canal wall down mastoidectomy in 2006. Four years later, the patient complained of right ear fullness; an examination determined that the right ear canal wall was nearly obliterated by a soft tissue mass. Surgery determined that a papilloma-like mass filled the mastoid cavity. The tumor was surgically resected by revision canal wall down mastoidectomy with canaloplasty. Histologically, it was determined to be an inverted papilloma. There has been no evidence of recurrence to date.